I have a Philips Streamium 3900 and it connects ok with my system but I can not get any of my iTunes playlist over to the Twonky system.
All our music is on the NAS with a Twonky server and the playlists are in the iTunes folder on the main PC as this is the configuration iTunes let you set up.

I also have a Sonos system and that find the playlists without any problems so I initially thought that that would be the same with the streamium.